Withdrawal

Withdrawal is the set of physical and psychological symptoms that appear when a person stops or sharply reduces a substance the body has adapted to.

It reflects the nervous system rebounding from the substance's effects. Alcohol and sedative withdrawal can be dangerous, bringing tremor, sweating, anxiety, seizures and, in severe cases, delirium. Opioid withdrawal produces muscle aches, sweating, diarrhea, vomiting and intense craving that is rarely life-threatening but very uncomfortable. Nicotine and caffeine withdrawal bring irritability, headache and poor concentration, and cannabis withdrawal can include irritability, sleep disturbance and reduced appetite.

Clinicians assess withdrawal with the substance history and standardized scales such as the CIWA for alcohol and the COWS for opioids, which guide whether medical supervision is needed. Withdrawal is one of the diagnostic criteria for substance use disorder. Cannabidiol has been examined in early studies of withdrawal-related symptoms in several substances, and there is no approved use.